Motor vehicles typically include armrests which are pivotable between raised and lowered positions for the convenience of passengers. When such an armrest is in its raised position, it is desirable to be able to prevent it dropping to its lowered position in the event of a sudden deceleration. A locking mechanism for a motor vehicle armrest is now required in many vehicles.
Typical known armrest locks require release before the armrest can be lowered. However, such a system requires that the potential user of the armrest be acquainted with the manner of operation so as to be able to lower the armrest, and rear seat passengers, for whom armrests are most frequently provided, do not have access to an instruction manual or the inclination to investigate how to release the lock which allows the armrest to be lowered.
Accordingly, there exists a need for freely pivotable armrests which are automatically lockable in an upright position in the event of a sudden deceleration. The same need exists for child restraint seat backs, ski lids, etc.
U.S. Pat. No. 4,579,384 provides an armrest lock for locking an armrest in its raised position as a result of its own inertia in the event of a sudden deceleration of the vehicle. The device includes a freely pivotable latch which engages a projecting rib on an armrest linkage when suddenly decelerated. A problem with such design is that the freely rotating latch may rattle or jam, and a hard deceleration may cause bouncing of the pivotable latch which may prevent the device from latching. Accordingly, it is desirable to provide an inertia latch for vehicle armrest or other seat component which is smoothly operating, reliable and rattle free.